Glass may be used for the door of a home appliance. For example, the glass may be used for the door of a refrigerator. If the glass is applied to the door of the refrigerator, a user has an advantage in that the user may easily see foods stored in the refrigerator through transparent glass without opening the door.
However, since the glass represents a lower insulating rate due to the intrinsic characteristic of the glass, chilly air stored in the refrigerator may be leaked to the outside through the glass. In particular, when the glass constitutes a glazing in a single layer, the lower insulating rate may be a more serious problem.
To compensate for the lower insulating rate, the glass may constitute a double glazing or a vacuum glazing including at least two glazings. The double glazing may be formed by injecting specific gas, which has a lower heat transfer coefficient, between the two glazings.
In addition, the vacuum glazing may be formed by making, in the vacuum state, the space between the two glazings. The vacuum glazing is more advantage than the double glazing in terms of an ability to block heat from being transferred to an inside or an outside of glass.
Regarding the vacuum glazing, there are introduced following related arts.                1. Korean Unexamined Patent Publication No. (publication date): 10-2009-0036709 (Apr. 15, 2009).        2. Title of disclosure: Vacuum window glass and method of fabricating the same        
The related art has the following problems.
First, as the thicker thickness of an adhesive (glass frit) for bonding the two glazings to each other is formed (to about 8 mm or more) to improve the adhesive force between two glazings, heat is transferred through the bonding part, thereby forming dew. In addition, an addition heater is required to prevent the dew from being produced.
Second, as the thicker vacuum layer is formed due to the thicker adhesive, the height of a spacer to support the two glazings between the two glazings is increased. Accordingly, the spacer may fall down or may not be stably installed in the manufacturing process of the vacuum glazing.
In addition, when the diameter of the spacer is increased to the above problem, the insulating performance of the vacuum glazing may be deteriorated.